Define the three classifications of burn injury and their characteristics.

In 2012 we began writing a series of articles targeted to emergency medical services professionals on best practices in the care of patients with burn injuries.1–3,11 Our initial article focused on the most common burn injury, thermal burn.1

Over the past decade, thermal burn injury outcomes have continued to improve as science has evolved. This updated review will be presented in three sections and focus on the basics of initial management (the first 60–90 minutes following the injury) for a thermal burn injury, to include care guidelines that have changed over the past 10 years.

This first section will provide an overview and cover the anatomy of the area impacted and burn injury classification. The second will include general assessment, ABCDEs, and wound care. The last will discuss pain management and complex and critical burn injuries.

By the Numbers

Burn injury involves the integumentary system—the largest body system, involving the hair, skin, and nails. The skin makes up the largest part of the integumentary system. There are 486,000 burn injuries each year in the United States.4

According to the American Hospital Association, there were 5,198 community hospitals in the U.S. with 792,417 staffed beds in 2019.5 In total, 132 of these hospitals self-identified as burn centers, with approximately 2,000 beds collectively,6 yielding a ratio of approximately one burn center for every 40 hospitals and one “burn bed” for every 400 beds.

Burn injuries are rare, and there are very few locations where serious burn injuries are routinely managed. Regardless of prevalence, just as patients with trauma injuries are best managed at dedicated trauma centers,7,8 patients with thermal burn injuries are best managed in verified burn centers.9

According to the National Burn Repository (NBR), in 2011 (reflecting data for 2010), the patient with a 50% total body surface area (TBSA) injury would stay 75 days in the hospital on average.6 By the 2016 NBR report (reflecting data for 2015), that stay had decreased to approximately 50 days.10 During the same period, while total burn injuries decreased, the number being treated in burn centers went up. On average, more burns are being treated at burn centers (i.e., admissions) today than in 2010, though their average length of stay is shorter. Also found in the 2016 NBR was that the average hospital charge for a burn-injured patient who survived the burn injury with a 50%–59% TBSA of burn injury was more than a million dollars.10

Although it can be anticipated that the burn-injured patient will require prolonged hospitalization provided they survive the injury, it’s critical that the immediate postinjury phase is managed in a manner to preserve quality of life and optimize patient outcomes.

Finally, much of the science that informs the initial care of burn patients is based on military medical experiences. As with the Korean and Vietnam conflicts, medical lessons learned from the contemporary Iraq and Afghanistan conflicts have contributed greatly to improving how the burn-injured patient is managed in both military and civilian medicine.12,13

Anatomy of a Burn Injury

There are three layers of skin in the human body: epidermis, dermis, and subcutaneous (fatty) tissue (also known as hypodermis). The epidermis is, in essence, the outer protective coating of our skin. This layer is thinnest on the eyelid and thickest on the palms and soles of the feet.

The dermis also varies in thickness but contains specialized cells such as hair follicles, sebaceous (oil) and eccrine (sweat) glands, and certain nerve cells. The subcutaneous tissue (hypodermis) is a layer of fat in which the larger blood vessels and nerves are located, as well as connective tissue.

A thermal burn occurs when the skin is exposed to a heat source outside typical ranges for comfort to the degree that damage occurs. The greater the heat transfer and duration of exposure, the greater the severity of the injury.

For all burn types, thermal injuries are the most common burns. Burn injuries are classified based on the nature, size, and depth of the burn and what part of the body is injured. The TBSA is based on the Rule of Nines calculation. The final part of this series will discuss serious and critical burn injuries based on burn center referral criteria.14

Classifications of Burn Injury

Burns are classified according to their severity.

Superficial (first-degree burn)—The most common thermal burn injury is a superficial burn, also described as a first-degree burn. Superficial burns are characterized by reddened skin. The lighter a patient’s normal skin tone/complexion, the more obvious the color change will be; patients with darker normal skin tone/complexion will be less obvious but share the same degree of injury. This is a painful burn for all patients.

The most common cause of superficial burns is sunburn. While painful, even when much of the body is involved with a superficial burn, this condition typically does not require EMS activation or hospitalization for the burn injury alone.

Superficial burns are not included in TBSA calculations (i.e., the Rule of Nines). One of the most common mistakes made by clinicians caring for patients with burn injuries is to include the superficial portion with those of the more significant partial-thickness (second-degree) and full-thickness (third-degree) burns when determining the TBSA.

Partial-thickness (second-degree burn)—The partial-thickness burn is characterized by blistering and is quite painful. This is the most common burn injury with EMS activation and most commonly treated in the ED. Partial-thickness burns do not include superficial/first-degree burns.

Full-thickness (third-degree burn)—The full-thickness burn is characterized by either charring or a thick leathery appearance of the skin. Pain is an unreliable symptom, as patients may report the pain created by the injury as extreme, not painful at all, or anywhere in between. A full-thickness burn includes damage and destruction of the subcutaneous fatty tissue, where nerve endings are located. These patients will often report that the injury is painful, but this is commonly due to the partial-thickness injury involving the area contiguous to the full-thickness burn site(s).

Other classifications of burn injury—The phrase deep partial-thickness burn also exists in the academic literature. However, it is a diagnosis typically made at a verified burn center, and that distinction does not impact care of the patient in the prehospital or emergency department setting. Thus, it is not discussed in depth here. For the sake of emergency care, if there are blisters, consider it a partial-thickness burn, and with charred skin or skin with a leathery appearance, identify it as a full-thickness burn.

Very serious burn injuries have rarely been described as either fourth- or fifth-degree burns. These classifications are used to describe full-thickness burns that involve muscle tissue (fourth-degree) or bone (fifth-degree). These descriptions have been found in legal literature but not in medically focused academic literature.15 For this work, the nomenclature will be superficial, partial, and full-thickness burn injury.

The next part of this series will focus on general assessment, ABCDEs, and wound care.

13. National Academies of Sciences, Engineering, and Medicine. A National Trauma Care System: Integrating Military and Civilian Trauma Systems to Achieve Zero Preventable Deaths After Injury. Washington, DC: The National Academies Press, 2016.

14. American Burn Association. Resources for Optimal Care of the Injured Patient, http://ameriburn.org/wp-content/uploads/2017/05/burncenterreferralcriteria.pdf.

Randy D. Kearns, DHA, MSA, FACHE, FRSPH, CEM, is an assistant professor in the College of Business Administration at the University of New Orleans and a retired clinical assistant professor from the School of Medicine at the University of North Carolina.

Michael W. Hubble, PhD, MBA, NRP, is an instructor in the Emergency Medical Science Department at Wake Technical Community College.

Amanda P. Bettencourt, PhD, APRN, CCRN-K, ACCNS-P, is a research fellow and TACTICAL Scholar at the University of Michigan School of Nursing.

James C. Jeng, MD, FACS, is a physician at Crozer-Keystone Health System and Nathan Speare Regional Burn Treatment Center, professor of surgery at Icahn School of Medicine, Mount Sinai Healthcare System, and chair of the Disaster Subcommittee of the Organization and Delivery of Burn Care Committee for the American Burn Association.

Jeffrey E. Carter, MD, FACS, is associate professor of surgery at the Louisiana State University Health Science Center New Orleans and medical director of the University Medical Center Burn Center, New Orleans.